Buildings, outside sculptures and other things often develop a residue of soot, ash, or other foreign material build-up, including oxidation. Foreign material build-up impairs the appearance of buildings and art, and also promotes deterioration of the surface of the building or sculpture. Consequently, it is beneficial to periodically clean a building or sculpture surface. However, it is important that any cleaning not harm the surface of the building or the artwork. Therefore, a method and system for cleaning surfaces without damaging the surface material is desired.